title: The role of temporary biventricular pacing in the cardiac surgical patient with severely reduced left ventricular systolic function.
abstract: OBJECTIVE
  The objective was to evaluate the effects of atrial synchronous biventricular pacing in postoperative patients with severe cardiomyopathy.
  
  
  METHODS
  Atrial synchronous biventricular pacing epicardial leads were placed during cardiac surgery in patients with an ejection fraction of 30% or less. Patients were randomized to usual care pacing, the mode determined by the surgeon (excluding atrial synchronous biventricular pacing) with a preference for no pacing or atrial pacing (atrial inhibited pacing); atrial synchronous right ventricular pacing; or atrial synchronous biventricular pacing. Pacing was continued until cessation of hemodynamic support. At 12 hours postoperatively, patients were randomly tested in each mode (atrial inhibited, atrial synchronous right ventricular, and atrial synchronous biventricular pacing), and thermodilution outputs were measured.
  
  
  RESULTS
  Forty subjects were randomized. Groups were similar in age (66 +/- 11 years), gender (85% were male), ejection fraction (23% +/- 6%), QRS duration (111 +/- 30 ms), and surgical indication. There was no difference in stroke index or cardiac index at 12 hours, duration of inotropic or intra-aortic balloon pump support, intensive care unit, or hospital length of stay. On comparative crossover testing, stroke volume was similar with atrial inhibited pacing and atrial synchronous biventricular pacing (59.3 +/- 13.4 vs 57 +/- 12.1, respectively, P = not significant); however, atrial synchronous right ventricular pacing was inferior (56 +/- 12.9, P < .05 for comparison with atrial inhibited pacing). When compared with atrial inhibited pacing, atrial synchronous biventricular pacing showed a positive response in 17% of subjects (increase in stroke volume >or= 5%), whereas 41% had a 5% or greater decrease in stroke volume.
  
  
  CONCLUSIONS
  Pacing mode affects stroke volume in patients with severe cardiomyopathy. Atrial synchronous biventricular pacing was helpful in a minority, but in 41% it compromised stroke volume.
authors.affiliation: William Beaumont Hospital, Royal Oak, Michigan 48073, USA.
authors.forename: Rudolph F
authors.initials: RF
authors.lastname: Evonich
authors.forename: John C
authors.initials: JC
authors.lastname: Stephens
authors.forename: William
authors.initials: W
authors.lastname: Merhi
authors.forename: Srinivas
authors.initials: S
authors.lastname: Dukkipati
authors.forename: Nicholas
authors.initials: N
authors.lastname: Tepe
authors.forename: Francis
authors.initials: F
authors.lastname: Shannon
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Altshuler
authors.forename: Marc
authors.initials: M
authors.lastname: Sakwa
authors.forename: Joseph
authors.initials: J
authors.lastname: Bassett
authors.forename: Eric
authors.initials: E
authors.lastname: Hanson
authors.forename: Judy
authors.initials: J
authors.lastname: Boura
authors.forename: William W
authors.initials: WW
authors.lastname: O'Neill
authors.forename: David E
authors.initials: DE
authors.lastname: Haines
mesh_terms: D000368:Aged; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D003131:Combined Modality Therapy; D017023:Coronary Angiography; D001026:Coronary Artery Bypass / Q000009:adverse effects / Q000379:methods*; D023921:Coronary Stenosis / Q000175:diagnosis / Q000401:mortality* / Q000628:therapy*; D018592:Cross-Over Studies; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D054143:Heart Failure, Systolic / Q000175:diagnosis / Q000628:therapy*; D006439:Hemodynamics / Q000502:physiology; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care / Q000379:methods; D011336:Probability; D011446:Prospective Studies; D012016:Reference Values; D018570:Risk Assessment; D012720:Severity of Illness Index; D013318:Stroke Volume; D016019:Survival Analysis; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000628:therapy